A gas turbine generally comprises a compressor, a combustor, and a turbine, wherein the compressor provides compressed air generated by a plurality of compressor blades to the combustor. The plurality of compressor blades are engaged in a tangential groove of a disk and a plurality of spacers are engaged in the tangential groove between the plurality of compressor blades. Once the compressor blades and the spacers are installed sequentially in the tangential groove, the last remaining space in the tangential groove cannot be filled and secured by the compressor blades or the spacers because the remaining space is not enough for the spacer to be installed in the tangential groove. Thus, in the conventional design, a multi-piece spacer is used in such a manner that multiple parts are inserted into the remaining space and combined with each other. However, the prior art multi-piece spacer comprises so many parts including bolts and nuts that it is possible for multi-piece parts to disassemble and be released into the compressor blades, thereby causing damage to the compressor blades.